Work channeling device for sewing machines



March 18, 194.7. c, NE 2,417,516

WORK CHANNELING DEVICE FOR SEWING MACHINES Filed Nov. 7, 1945' Patented Mar. 18, 1947 WORK CHANNELING DEVICE FOR SEWING .MACHINES Carl A. Newhall, Peabody, Mass, assignor to United Shoe Machinery Corporation, Flemington, N. J a corporation of New Jersey Application November 7, 1945 Serial No. 627,215

7 Claims. 1

The present invention relates to work channeling or grooving devices for sewing machines and more particularly to improvements in a device of this nature having a grooving knife mounted on the presser foot of a shoe sewing machine, an example of which is disclosed in United States Letters Patent No. 2,225,301, granted December 17, 1940, on application of Otto R. Haas.

The work channeling device of the patent above referred to comprises a presser foot having a lug provided with a, circularbore within which a groove cutting knife is clamped, the presser foot having means thereon for preventing rotation of the knife in the bore. In the patented device, if the knife requires adjustment transversely of the seam in the work operated upon, it is necessary to loosen the presser foot from its supporting lever in order to bring the knife into line with the seam. While the patented construction has many advantages not found in othersimilar prior art devices, it frequently is inconvenient and undesirable to loosen the Presser foot merely for knife adjusting purposes.

Accordingly, it is an object of the present invention to provide a work channeling or grooving device of relatively simple construction similar to that in the machine disclosed in the patent, in which it is unnecessary to loosen the presserfoot from its adjusting lever, and in which accurate alinement of the cutting edge on the knife with the seam line in the work is easily accomplished. Another object of the invention is to provide an inexpensive presser foot and groovecutting device in which the depth of groove cut may readily be adjusted without the exercise of special attention on the part of the operator, particularly when the knife is removed for sharpening or examination of its cutting edge.

In the preferred embodiment of the present invention, a. sewing machine presser foot is provided formed with a work engaging face and a lug having a bore transverse to the Work engaging face of the presser foot for reception of a grooving knife projecting beyond the work engaging face of the presser foot in which conveniently arranged clamping means are arranged for securing the knife comprising a pair of spaced adjusting members engaging the knife to cause the knife to be rotated in the bore when one of the adjustable members is disengaged from the knife and the other actuated further to reclamp the knife within the here. If the bore is made circular and the cutting edge of the knife is located at one side of the central axis of the bore, then the edge will .be moved transversely of the seam line in the desired manner. as the knife rotates. By this construction, the clamping members not only secure the knife in position but also enable the cutting edge of the knife to be shifted into proper alinement with the point of operation of the sewing machine without disturbing the presser foot or its supporting lever or otherwise interfering with previously determined adjustments in the machine.

In the present form. of the invention, the clamping members include setscrews engaging a fiat surface along one side of the knife, thus forming an effective seat against which the screws may act. Accordingly, when one of the screws is loosened and the other tightened, the knife is rotated in. one direction or the other.

Preferably, the knife is provided with means for adjusting also the depth to which its edge cuts the work and, in the illustrated form, this feature comprises a screw threaded into the upper end of the knife with its head bearing on the presser foot outside the knife receiving bore therein.

The several features of the present invention will be clearly understood from an inspection of the accompanying drawings, in which Fig. l is a plan view of a channel or groove cutting device embodying the features of the present invention illustrating the operation of the machine to which it is applied;

Fig. 2 is a view in left-hand side elevation of the device illustrated in Fig. 1;

Fig. 3 is a view partly in front elevation and partly in section of the cutting device;

Fig. 4 is a sectional view taken along the line IV-IV of Fig. 3;

Fig. 5 is a detail end view of the cutting knife; and

Fig. '5 is a side view of the same.

As illustrated in the drawings, the device is a further improvement over a previous channel cutting device illustrated in United States Letters Patent to Haas above referred to and No.

1,048,719, granted December 31, 1912, upon an application filed in the name of William C. Meyer, and is intended for use in an outsole shoe sewing machineparticularly for shoe repair work. The device is intended to take the place of the regular presser foot of the machine and is secured to a presser foot lever it. a portion of which is illustrated in Fig. l by means of screws i2 passing through the lever and into threaded engagement with the device. The presser foot portion to of the device has a lower work engaging face It for clamping the work indicated at l8 against a work support (not shown), during operation of the stitch forming devices including a needle indicated in section at 20.

During operation of the machine, the needle 20 inserts a line of stitching 22 within a groove 24 formed in line with the point of operation of the needle and, after the stitches are formed, they are concealed by the action of a rub-down portion 25 of the presser foot for squeezing the edges of the groove together about the exposed threads of the stitches.

To cut the channel or groove for the seam in the work, the presser foot has formed on it a lug 26 having a circular bore 28 (see Fig. 2) the axis of which is inclined at an acute angle to the work engaging face of the presser foot. Received within the bore 28 is a grooving knife 30 having its lower endprovided with a cutting edge 32. The cutting edge 32 forms a continuation of the outer circumference of the cylindrical shank on the grooving knife, the sides of the cutting edge being ground away at an angle to each other, as best shown in Figs. and 6. When disposed within the bore 28 with its cutting edge projecting a short distance below the face It of the presser foot, the knife drags along the surface of the work to cut a groove.

To insure that the edge of the knife will cut a groove in line with the point of operation of the needle so that the threads of the seam will fit accurately within the groove, and to secure the knife in the circular bore according to a feature of this invention, the lug 26 is drilled at opposite sides of the axis of the bore 28 and threaded to receive two clamping screws 34 and 36 passing through the lug into engagement with the knife 38. The arrangement of the screws 34 and 36 is such that they not only secure the knife within the bore of the presser foot but also enable adjustment of the cutting edge 32 of the knife transversely of the seam line in the work operated upon.

To enable the cutting edge 32 of the knife to be adjustably shifted transversely of the seam line, in the embodiment of this feature, the clamping screws 34 and 36 act on the knife not only at opposite sides of the axis of the bore in the presser foot but upon a flat 38 along the entire length of one side of the knife, forming a seating surface for the inner ends of the screws (see Fig. 4). When the screw 34 is loosened and the screw 36 is tightened, a rotational movement will be imparted to the knife, shifting the cutting edge 32 toward the rear of the machine. When the screw 36 is loosened and the screw 34 tightened, reverse rotation and shifting movement takes place. Thus, comparatively simple means is provided for bringing the cutting edge of the knife into line with the point of needle operation. The groove cut by the knife therefore may be accurately located in advance of the sewing operations to insure that the exposed threads of the seam inserted by the machine will lie at the center of the groove so that, when the edges of the groove are brought together by the rub-down portion 25 of the presser foot, the exposed threads will be fully concealed.

To adjust the depth to which the grooving knife will cut, the knife is provided with a central threaded opening 40 Within which is received a screw 42 the head of which bears upon the upper surface of the lug 26 of the presser foot. To prevent undesired rotation of the depth adjusting screw 42, the shank of the screw between the upper end of the knife and the head of the screw is surrounded by a compression spring 44 which provides sufficient friction to hold it in place but insufficient friction to prevent turning the screw with a screw driver. Thus the clamping screw 34 or 36 may be loosened and th knife withdrawnfrom the bore 28, for sharpening or examination of the cutting edge, and replaced without danger of change in the depth to which the knife will cut. Furthermore, in rotating the knife by loosening and tightening the clampin screws, no effect on the depth of cut will be produced, the weight of the knife holding it at the lowermost position permitted by the adjusting screw 42 within the bore 28.

The nature and scope Of the invention having been indicated and a particular embodiment having been described, what is claimed is:

1. A work channeling device for a shoe sewing machine, having a presser foot formed with a work engaging face and a lug having a bore the axis of which is transverse to the work engaging face of the presser foot, and a work grooving knife received in the bore with its cutting edge projecting beyond the work engaging face of the presser foot, in combination with means for clamping the knife and shiftingits cutting edge transversely of the seam line in the work operated upon, comprising a pair of spaced adjustable members engaging the knife at locations to cause the knife to be rotated in the bore when one of said members is disengaged from the knife and the other actuated further to clamp the knife.

2. A channeling device for a shoe sewing machine, having a presser foot formed with a work engaging face and a lug provided with a circular bore the axis of which is transverse to the work engaging face of the presser foot, and a fiat sided work grooving knife received within the bore with its cutting edge projecting beyond the work engaging face of the presser foot, in combination with a pair of spaced setscrews for clamping the knife and shifting its cutting edge transversely of the seam line in the work operated upon, arranged to engage the flat of the knife at opposite sides of the axis of the bore in the presser foot and to rotate the knife in the bore when one of the setscrews is loosened and the other tightened.

3. A work channeling device for a shoe sewing machine, having a presser foot formed with a work engaging face and a lug provided with a circular bore the axis of which is transverse to the work engaging face of the presser foot, in combination with a generally cylindrical work grooving knife fitting the bore in the presser foot with its cutting edge near its cylindrical surface and a flat along one side, and a pair of spaced setscrews for clamping and shifting the cutting edge of the knife transversely of the seam line in the work operated upon, arranged to engage the flat of the knife at opposite sides of the axis of the bore in the presser foot and to rotate the knife in the bore when one of the setscrews is loosened and the other tightened.

4. A work channeling device for a shoe sewing machine, having a presser foot formed with a work engaging face and a lug provided with a circular bore the axis of which is transverse to the work engaging face of the presser foot, in combination with a generally cylindrical Work grooving knife fitting the bore in the presser foot with its cutting edge near its cylindrical surface and a flat along one side, a pair of spaced setscrews for clamping and shifting the cutting edge of the knife transversely of the seam line in the work operated upon, arranged to engage the flat of the knife at opposite sides of the axis of the bore in the presser foot and to rotate the knife in the bore when one of the setscrews is loosened and the other tightened, and means for adjusting the depth to which the edge of the knife cuts the work.

5. A work channeling device for a shoe sewing machine, having a presser foot formed with a work engaging face'and a lug provided with a circular bore the axis of which is transverse to the work engaging face of the presser foot, in combination with a generally cylindrical work grooving knife fitting the bore in the presser foot with its cutting edge near its cylindrical surface and a flat along one side, a pair of spaced setscrews for clamping and shifting the cutting edge of the knife transversely of the seam line in the work operated upon, arranged to engage the flat of the knife at opposite sides of the axisof the bore in the presser foot and to rotate the knife in the bore when one of the setscrews is loosened and the other tightened, and means for adjusting the depth to which the edge of the knife cuts the work comprising a screw threaded into the upper end of the knife with its head bearing on the presser foot outside the knife receiving bore.

6. A work channeling device for a shoe sewing machine, having a presser foot formed with a work engaging face and a lug provided with a circular bore the axis of which is transverse to the work engaging face of the presser foot, in combination with a generally cylindrical work grooving knife fitting the bore in the presser foot with its cutting edge near its cylindrical surface and a flat along one side, a pair of spaced setscrews for clamping and shifting the cutting edge of the knife transversely of the seam line in the work operated upon, arranged to engage the flat of the knife at opposite sides of the axis of the bore in the presser foot and to rotate the knife in the bore when one of the setscrews is loosened and the other tightened, and means for adjusting the depth to which the edge of the knife cuts the work comprising a screw threaded into the upper end of the knife with its head bearing on the presser foot outside the knife receiving bore, and means for preventing rotation of the depth adjusting screw during rotation of the knife in the bore.

7. A work channeling device for a shoe sewing machine, having a presser foot formed with a work engaging face and a lug having a circular bore, and a work grooving knife received in the bore with its cutting edge projecting beyond the work engaging face of the presser foot, in com bination with means for clamping the knife and shifting its cutting edge transversely of the seam line in the work operated upon, comprising a pair of spaced adjustable members engaging the knife at locations to cause the knife to be rotated in the bore when one of said members is disengaged from the knife and the other actuated further to clamp the knife.

CARL A. NEWHALL. 

